Methods for determining the invasiveness of a bladder tumor

ABSTRACT

Complexes (which include basement membrane components) and their polypeptide components are found to be related to the invasiveness of a bladder tumor. Detection of such complexes or constituents in a urine sample by immunological or non-immunological methods permits determining the invasiveness of a bladder tumor.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent application Ser. No. 08/178,219, filed Jan. 6, 1994; which is a continuation of U.S. patent application Ser. No. 08/096,490, filed Jul. 23, 1993, abandoned; which is a continuation-in-part of U.S. patent application Ser. No. 07/721,756, filed Jun. 26, 1991, issued as U.S. Pat. No. 5,264,370; which is a continuation-in-part of U.S. patent application Ser. No. 283,397, filed Dec. 12, 1988, abandoned.

TECHNICAL FIELD

The present invention relates generally to determining the invasiveness of a bladder tumor that results in the release of complexes which include basement membrane components. This invention is more particularly related to determining bladder tumor invasiveness by detection of such complexes or polypeptide components thereof by a variety of methods, including immunological and non-immunological means.

BACKGROUND OF THE INVENTION

A challenge to medicine since its inception has been the development of methods that permit rapid and accurate detection of diseases. Despite advances in diagnostic technology over the years, the current techniques for the diagnosis of many diseases are either inadequate or cost prohibitive for wide scale application. One such disease is bladder cancer.

As a worldwide problem, it was estimated that there are 50,900 new cases of bladder cancer per year in Western Europe, 3,700 in Japan and 34,000 in North America (WHO 1984), with at least 3 to 4 times this number of patients attending hospitals for follow-up or treatment. Bladder cancer affects about three times as many men as women. It is the fourth most common form of cancer in men and the ninth most common in women in the United States. Over 90% of bladder cancers are of the transitional cell type (transitional cell carcinoma or "TCC").

Bladder cancer may present in several ways, according to the stage when discovered. A diagnosis of TCC of the bladder or urinary tract structures is staged and graded, according to the following system, based on biopsy or surgical specimen results.

    ______________________________________                                         Stages of Primary Bladder Cancer                                               Stage of Primary                                                               Bladder Tumor                                                                             Description                                                         ______________________________________                                         Tis (Cis)  Tumor in situ (carcinoma in situ); flat tumor                       Ta         Superficial (noninvasive) papillary tumor which                                does not infiltrate beyond the basement                                        membrane or superficial mucosa                                      T1         Tumor which infiltrates the lamina propria                                     muscularis mucosa (or submucosa)                                    T2         Tumor which invades the superficial muscle                                     (muscularis propria)                                                T3         Tumor which invades the deep muscle or                                         perivesical fat                                                     T4         Tumor which invades any of the following: the                                  prostate, vagina, uterus, pelvic wall, or                                      abdominal wall                                                      ______________________________________                                    

The tumor grade is based on the degree of anaplasia, or loss of cell differentiation.

    ______________________________________                                         Grades of Primary Bladder Cancer                                               Grade of Primary                                                               Bladder Tumor      Description                                                 ______________________________________                                         Grade I (low)      Slight anaplasia                                            Grade 11 (medium)  Moderate anaplasia                                          Grade Ill (high)   Severe anaplasia                                            ______________________________________                                    

Bladder cancer occurs in two major forms: superficial (Tis, Ta, T1) and invasive (≧T2). Superficial tumors may have variable grade, with higher grade superficial tumors having poorer prognosis. About 70% of superficial tumors will develop one or several recurrences during a five-year follow-up period. The major risk is that the tumor will become invasive. Most invasive tumors are subsequently manifested as high grade as well as stage.

The invasive form of bladder cancer accounts for approximately 20%-30% of all bladder cancer. Invasive bladder cancer starts in the mucosa lining the bladder, invades through the basement membrane to reach muscle wall, and finally the pelvic tissues and surrounding organs, including local lymph nodes. The outlook depends on the stage and grade, with five-year survivals from 11%-60%. The treatment is by radiotherapy, chemotherapy and surgery.

Patients with invasive bladder tumors are monitored by urine cytology and check cystoscopy. Although cytology is a non-invasive and less difficult procedure, it can be prone to error or uncertainty. For example, a positive result by cytology may be helpful, but a negative result cannot be taken as evidence of the absence of a tumor. Further, the reporting varies greatly with the cytologist's experience. Cystoscopy is an invasive, expensive and occasionally hazardous procedure, as it is frequently carried out under anesthesia. Despite the uncertainties associated with cystoscopic checks, they are nevertheless still considered by many medical practitioners as the diagnostic tool of choice because of the absence of better tests.

Malignancies that are low stage-superficial or noninvasive (Ta, Tis, T1)-respond to endoscopic therapy. Yet, as noted above, recurrence at the same or another site in the bladder is relatively common. Depending on the stage and grade of the superficial tumor, progression to an invasive (≧T2) tumor may occur. Since invasive lesions respond poorly to endoscopic therapy and the treatment of choice is cystectomy, it is therefore of critical importance to be able to monitor all patients with a confirmed diagnosis of bladder cancer in order to detect disease recurrence and/or progression.

Thus, there is a need in the art for a method of determining the invasiveness of a bladder cancer. The present invention fulfills these needs and further provides other related advantages.

SUMMARY OF THE INVENTION

Briefly stated, the present invention provides, in one aspect, methods for determining the invasiveness of a bladder tumor. In one embodiment, the method comprises the steps of: (a) isolating a urine sample from a warm-blooded animal suspected of possessing a bladder tumor; (b) detecting in the sample the polypeptide composition of a complex which includes basement membrame components, wherein the complex comprises polypeptides selected from a group of polypeptides with approximate molecular weights of 245,000; 190,000; 165,000; 140,000; 125,000; 98,000; 82,000; 74,000; 55,000; 43,000; 35,000; 26,000; and 16,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and (c) determining the invasiveness of the bladder tumor based on the polypeptide composition of the complex.

In another embodiment, the method for determining the invasiveness of a bladder tumor comprises the steps of: (a) isolating a urine sample from a warm-blooded animal suspected of possessing a bladder tumor; (b) measuring in the sample the amount of a first polypeptide of a complex which includes basement membrane components, wherein the first polypeptide has an approximate molecular weight of 165,000; 140,000; or 125,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; (c) measuring in the sample the amount of a second polypeptide of the complex, wherein the second polypeptide has an approximate molecular weight of 98,000; 82,000; 74,000; 55,000; 43,000; 35,000; 26,000; or 16,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and (d) calculating the ratio of the amount of the first polypeptide to the amount of the second polypeptide, and determining therefrom the invasiveness of the bladder tumor.

In another embodiment, the method for determining the invasiveness of a bladder tumor comprises the steps of: (a) isolating a urine sample from a warm-blooded animal suspected of possessing a bladder tumor; (b) measuring in the sample a polypeptide of a complex which includes basement membrane components, wherein the complex comprises polypeptides selected from a group of polypeptides with approximate molecular weights of 165,000; 140,000; 125,000; 98,000; 82,000; 74,000; 55,000; 43,000; 35,000; 26,000; and 16,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and (c) determining therefrom the invasiveness of the bladder tumor.

In yet another embodiment, the method for determining the invasiveness of a bladder tumor comprises the steps of: (a) isolating a urine sample from a warm-blooded animal suspected of possessing a bladder tumor; (b) measuring in tile sample the amount of a complex which includes basement membrane components, wherein the complex comprises polypeptides selected from a group of polypeptides with approximate molecular weights of 245,000; 190,000; 165,000; 140,000; 125,000; 98,000; 82,000; 74,000; 55,000; 43,000; 35,000; 26,000; and 16,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and (c) determining therefrom the invasiveness of the bladder tumor.

Another aspect of the present invention provides the cell line 1B4, as designated by ATCC No. 11389, and a monoclonal antibody produced by the cell line.

Other aspects of the invention will become evident upon reference to the following detailed description and attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart for the purification of bladder tumor analyte ("BTA") complexes frown urine of bladder cancer patients.

FIG. 2 graphically depicts A1.5M agarose gel filtration of a transitional cell carcinoma ("TCC") positive (Panel A) and negative urine (Panel B).

FIG. 3 graphically illustrates A15 agarose gel filtration of urines from bladder cancer patients with different stage and grade of TCC (Panels A-D).

FIG. 4 graphically depicts SDS-PAGE profiles of fractionated urines of TCC patients of different stage and grade (Panels A-E).

FIG. 5 graphically illustrates BTA dipstick activity versus tumor grade (Panel A) and tumor stage (Panel B) for A15 agarose purified fractions from 24 hour urines of bladder cancer patients and normals.

FIG. 6 graphically depicts fractionation of gel filtration purified BTA complexes on heparin agarose using a phosphate buffer system.

FIG. 7 graphically illustrates fractionation of heparin agarose purified complexes on DEAE-Biogel A.

FIG. 8 graphically depicts fractionation of gel filtration purified BTA complexes on heparin agarose using a Tris-buffer system.

FIG. 9 graphically illustrates SDS-PAGE of heparin agarose purified BTA complex from a TCC patient.

FIG. 10 graphically depicts 1B4 immunoreactivity with fractions from heparin agarose purification of complexes directly from urine of Ta Grade 1 patients.

FIG. 11 graphically illustrates a heparin capture ELISA system using 1B4 antibody and A15 purified complexes from TCC patients and normals. A total of 8 TCC negative and 16 TCC positive gel filtration isolated complexes were studied.

FIG. 12 graphically depicts a direct ELISA system using 1B4 antibody and A15 purified complexes as solid phase antigen.

FIG. 13 graphically illustrates the reactivity of 1B4 related clones with A15 purified complexes of TCC positive and negative patients.

FIG. 14 graphically depicts the distribution of 1B4 ELISA reactivities with urines from urological patients. A total of 26 patients were studied, with 15 confirmed TCC positives and 11 TCC negatives of which 3 were prostate cancers of stage B1, C3 and C1.

FIG. 15 graphically illustrates Western blot analyses of 1B4 antibody (Panel A) and related clones (such as 3D6, 12F3 and 8H2 which are Panel B) with complexes isolated from TCC positive urines as the solid phase antigen.

DETAILED DESCRIPTION OF THE INVENTION

As noted above, the present invention provides methods for determining the invasiveness of a bladder tumor based upon measuring complexes, which include basement membrane components, or polypeptide constituents thereof. Basement membranes (also referred to as basal lamina) are extracellular matrices separating organ parenchymal cells from connective tissue mesenchyme. Normally, parenchymal cells and stroma cells remain oriented on their respective side of the basement membrane, even during organ development and tissue repair. A number of diseases are apparently capable of disrupting basement membranes. The basement membrane is comprised of at least several identified proteins and peptide derivatives, including several specific types of collagen (e.g., Type IV and Type V), laminin, various types of cell adhesion molecules (CAMs), proteoglycans, and fibronectin.

Complexes which include basement membrane components have been found to survive in detectable concentrations in the biological samples of warm-blooded animals, including humans, possessing a disease which disrupts epithelial tissue. The basement membrane components in the complexes may be intact molecules, fragments thereof, or combinations of fragments and intact molecules. Complexes are indicative of a variety of diseases and are detectable in a variety of samples, with or without purification of such complexes. For example, complexes are associated with invasive cancers such as bladder cancers. Complexes are also associated with epithelial disorders (i.e., noninvasive or pre-invasive cancers and disorders unrelated to cancer) including epithelial inflammations, collagen degenerative diseases, and hepatitis. Epithelial inflammations include those which result from biopsies or deposits (e.g., "stones" in the bladder).

Representative types of biological samples include urine, cervical secretions, bronchial aspirates (including bronchial washings), sputum, saliva., feces, serum, synovial and cerebrospinal fluid. The type of biological sample in which complexes accumulate is dependent chiefly on the location of the particular disease. Urine is preferred for the detection of invasive urogenital cancers and urogenital epithelial disorders. Complexes from a urine sample may be isolated in substantial pure form. Briefly, for example, a sample may be fractionated by gel filtration and purified on heparin agarose or other anion or cation exchange media or by electroelution of specific polypeptides from polyacrylamide gels. A representative example of the purification of complexes is the isolation from a urine sample, as summarized in FIG. 1.

As disclosed herein, the polypeptide composition of a complex is related to whether the disease is an epithelial bladder disorder (including superficial cancers) or an invasive bladder cancer. By detecting the presence or absence of a particular complex, the presence or absence of a particular bladder disease may be determined. The presence of a bladder epithelial disorder (e.g., superficial cancer) is indicated by the presence in urine of complexes containing polypeptides with approximate molecular weights of 245k and 190k. Similarly, where complexes containing polypeptides with approximate molecular weights of 165k, 140k and 125k are detected in urine, the presence of invasive bladder cancer is indicated. These polypeptides are absent in urine of normal individuals. Complexes in a sample may be detected by a variety of nonimmunological or immunological means, as described below.

As disclosed in the present invention, the invasiveness of a bladder tumor may be determined based upon such complexes. In one embodiment, the invasiveness of a bladder tumor is determined from the amount of the complexes. In another embodiment, the invasiveness of a bladder tumor is determined from the polypeptide composition of the complex. In another embodiment, the invasiveness of a bladder tumor is determined from the ratio of the amounts of two polypeptides from the complex. In yet another embodiment, the invasiveness of a bladder tumor is determined from a single polypeptide of the complex. In may embodiment for determining the invasiveness of a bladder tumor, the presence or amount of a complex, its polypeptide composition, and/or one or more individual polypeptides may be detected by a variety of nonimmunological and immunological means.

For example, complexes which include basement membrane components may be detected by a physicochemical method. This method is based upon the ability of complexes released by a bladder cancer into urine to agglutinate a suspension of microparticles. The physicochemical method generally comprises contacting a urine sample with a suspension of microparticles which agglutinate in the presence of complexes which include basement membrane components. Subsequently, the presence of agglutination of the suspension of microparticles is detected, thereby allowing the determination of the presence of the complexes.

Microparticles suitable for use in this method include plastic latex, e.g., latex beads. Such a suspension of microscopic plastic particles is commonly prepared from polystyrene and derivatives thereof. The plastic may be in an underivatized form or in the form of derivatives, such as carboxylated or aminated. Typically, the microparticle has a diameter from about 0.01 to 5 microns, with about 0.25 microns preferred. It is advantageous to treat the suspensions of microparticles with one or more agents, such as bovine serum albumin, to block sites upon fire surface of the particles which are available for nonspecific interactions.

The suspension of microparticles agglutinates in the presence of a urine sample from a patient with a bladder cancer that results in the release of complexes which include basement membrane components. This agglutination reaction permits the detection of small amounts of complexes in the presence of relatively large amounts of exogenous protein present in the biological fluid being tested. Thus, pretreatment of the urine sample prior to testing may not be required. In the case of urine samples containing particulate contaminants, such as bacteria, cells, crystals, or other sediment, a brief centrifugation at low speeds sufficient to remove the particulate contaminants may be desirable, as is neutralizing the pH with buffer.

It will be evident to one skilled in the art that a variety of methods for detecting the presence of agglutination of a suspension of microparticles may be employed within the present invention. For example, a simple slide agglutination technique, such as those used extensively with small particle agglutination techniques, is suitable. In this technique, an aliquot of the suspension of microparticles is mixed with an aliquot of the specimen being tested on the surface of a glass slide. The reactants are mixed by rotating the slide manually or on a mechanical rotator. At time intervals, the appearance of the mixed reactants is judged relative to the appearance of the mixed reactants is judged relative to the appearance of a positive and negative control, which consists of known complex-containing and non-complex-containing specimen material, respectively. If, when viewed either macroscopically or microscopically, the unkown specimen being tested has caused agglutination of the microparticles in excess of that apparent in the negative control, the presence of complexes in the unknown is established.

Other methods of determining the extent of aggregation of a suspension may also be used (e.g., as described by Cohen & Benedek, U.S. Pat. No. 4,080,264; Kraemer, Am. J. Med. Tech., Vol. 48, No. 8, 1982; Looney, J. Clin. Immun. 7:90-95, 1984; and Grange et al., J. Immun. Meth. 18:365-375, 1977). Briefly, these include systems which detect the increase in rate of sedimentation of particles due to aggregation. Sedimentation may be judged visually or with the help of instrumentation which will record the increased rate of sedimentation by virtue of optical or other properties of the suspension. The distinctive light scattering properties of aggregates versus nonaggregated microparticles may be measured with a spectrophotometer or nephelometer set at any wavelength capable of measuring changes in these properties, e.g., 350, 660 or 700 nm.

As noted above, over 90% of bladder cancers are of the transitional cell. type (transitional cell carcinoma or "TCC"). The major risk is that the tumor will become invasive. The stage and grade of a tumor are measures of its invasive potential. Regardless of the particular method used to determine the amount of the complex in a urine sample, as disclosed in the present invention the total amount of complex is increasing from low to high invasiveness.

The polypeptide constituents of complexes may be identified. Typically, polypeptides are resolved by separation (e.g., by gel electrophoresis) under denaturing conditions (e.g., sodium dodecyl sulfate). Approximate molecular weights of polypeptides are assigned by comparison to polypeptides of known molecular weights. As disclosed herein, the invasiveness of a bladder tumor is related to the polypeptide composition of the complexes in the sample. For example, complexes from urine of patients with low grade non-invasive TCC of the bladder contain predominantly two high molecular weight polypeptides with approximate molecular weights of 245,000 ("245k") and 190,000 ("190k"). For complexes from patients with low grade invasive TCC, the predominant polypeptides shift from molecular weights of about 245k and 190k to molecular weights of about 165k, 140k and 125k. For complexes from patients with high grade invasive TCC, the polypeptide profile has shifted from the predominant polypeptides having molecular weights of about 165k, 140k and 125k to molecular weights of about 98k, 82k, 74k, 55k, 43k, 35k, 26k and 16k. All the foregoing approximate weights were determined on sodium dodecyl sulfate-polyacrylamide gel electrophoresis ("SDS-PAGE") by comparison to electrophoresis of polypeptide standards having known molecular weights.

As also disclosed herein, the invasiveness of a bladder cancer may be determined by comparing the amount of one polypeptide to the amount of another polypeptide. For example, the amount of a first polypeptide having an approximate molecular weight of either 165k, 140k, or 125k is compared to the amount of a second polypeptide having an approximate molecular weight of either 98k, 82k, 74k, 55k, 43k, 35k, 26k, or 16k. The 165k polypeptide is a preferred first polypeptide and the 98k or 43k polypeptide is a preferred second polypeptide. A particularly preferred combination of first and second polypeptides is the 165k and 43k polypeptides. Where the ratio of the amount of the first polypeptide exceeds the amount of the second polypeptide, the invasiveness of the bladder cancer is low. Conversely, where the ratio of the amount of the second polypeptide exceeds the amount of the first polypeptide, the invasiveness of the bladder cancer is high.

Alternatively, within the present invention, the invasiveness of a bladder cancer may be determined by measuring a single polypeptide of the complex. For example, the presence of the polypeptide having a molecular weight of about 245k or 190k indicates low grade non-invasive cancer. Conversely, the presence of the polypeptide having a molecular weight, for example, of about 43k or 98k indicates high grade invasive cancer. It will be appreciated by those of normal skill in the art that, based on the disclosure herein, other individual polypeptides described herein may be utilized in a similar manner (i.e., higher molecular weight species associated with low invasiveness and lower molecular weight species associated with high invasiveness).

Isolated complexes or individual polypeptide constituents are used to produce antibodies that specifically bind to an isolated complex, individual polypeptide, or both. Antibodies that specifically bind are those with an affinity of about 10⁶ liters/mol or greater. Either polyclonal antibodies or monoclonal antibodies may be generated. Polyclonal antibodies may be produced by immunization of an animal and subsequent collection of its sera. It is generally preferred to follow the initial immunization with one or more booster immunizations prior to sera collection. Monoclonal antibodies are generally produced by the method of Kohler and Milstein (Nature 256:495-497, 1975; Eur. J. Immunol. 6:511-519, 1976). Briefly, the lymph nodes and/or spleens of an animal injected with a complex or component are fused with myeloma cells to form hybrid cell lines ("hybridomas" or "clones"). Each hybridoma secretes a single type of immunoglobulin specific for the complex or component and, like the myeloma cells, has the potential for indefinite cell division.

A purified complex or polypeptide therefrom ("immunogen") is used for the immunization. Preferably, the animals are immunized with at least 100 ng each of the immunogen, most preferably greater than 500 ng each. For immunization, the immunogen may be adsorbed to a solid phase matrix, preferably to nitrocellulose paper. The paper is then introduced into the animal. Techniques for introduction of the adsorbed antigen preparation include implantation (U.S. Pat. No. 4,689,220) or solubilization of the solid phase and injection of the solubilized material (Knudsen, Anal Biochem. 147:285-288, 1985). The solid phase matrix may be solubilized in an appropriate organic solvent (e.g., DMSO) and either mixed with adjuvant or saline, or injected directly.

Alternatively, the immunogen may be injected in the absence of a solid matrix and/or adjuvant. Injection or implantation may be intraperitoneal, intra-foot pad, subcutaneous, intramuscular or intravenous, but preferably intraperitoneal. The animals may also be injected with antigen complexed with adjuvant, such as Freund's adjuvant. Single or multiple booster immunizations are used. Between one and seven days prior to the fusion date, preferably on days one through four, intravenous injections of the appropriate immunogen may be given daily.

Between one and seven days, preferably four days, after the administration of the final booster immunization, spleens or portions thereof are harvested from the immunized animals. At this time, the lymph nodes may also be harvested and included in the cell preparation. The harvested organs are minced using techniques which disrupt the structure of the organ, but which are not detrimental to the lymphocytes. The organs are preferably minced with scissors, passed through a mesh screen and mixed with growth medium to enrich the preparation for lymphocytes. The minced and strained tissue is harvested by centrifugation, then mixed with growth medium to form a cell suspension. The red blood cells may be lysed by adding a hypotonic or hypertonic solution to the cell suspension. A preferred method for cell lysis is to add distilled water to the suspensions and quickly return the suspensions to an isotonic state with a hypertonic sodium chloride solution. Any remaining tissue may be removed by filtration through gauze.

The harvested cell suspension is then mixed with a myeloma cell line, preferably one which is syngeneic with the immunized animal. Myeloma cell lines from various species are widely available through, for example, American Type Culture Collection, Rockville, Md. Myeloma cell lines commonly used include P3X63Ag8 (ATCC TIB 9), SP2/0-Ag14 (ATCC CRL 1581), OF (ATCC CRL 1646) and 210-RCY-Agl (Galfre et al., Nature 277:131, 1979). A preferred cell line is P3/NS1/1-Ag4-1 hereinafter referred to as NS-1 (ATCC TIB 18). The NS-1 cells are preferably tested to determine the cloning efficiency of the strain. This may be accomplished by cloning out the NS-1 strain by limiting dilution and carrying out test fusions with the individual NS-1 clones to find candidates with the highest fusion efficiencies.

The myeloma cells are cultured in an appropriate mammalian cell growth medium, a variety of which are generally known in the art and available from commercial sources. Mammalian cell lines are routinely grown between 36° C. and 40° C. under conditions which maintain an optimal pit between 6.0 and 8.0, preferably about pH 7.2. pH may be maintained through the use of a variety of buffer systems known in the art. A preferred buffer system involves growing the cells in a bicarbonate buffer in a humidified incubator containing CO₂, preferably about 7% CO₂.

The fusion between the lymphocytes from the immunized animal and the myeloma cells may be carried out by a variety of methods described in the literature. These methods include the use of polyethylene glycol (PEG) (Brown et al., J. Biol. Chem. 255:4980-4983, 1980) and electrofusion (Zimmerman and Vienken, J. Membrane Biol. 67:165-182, 1982). An electrofusion generator is commercially available from Biotechnologies and Experimental Research, Inc., San Diego, Calif.

Following the fusion, the cells are plated onto multi-well culture plates, preferably 96-well plates. A reagent which selectively allows for the growth of the fused myeloma cells over the unfused cells is added to the culture medium. A preferred selection technique uses HAT (hypoxanthine, aminopterin, thymidine) selection. Other selection techniques may also be used depending on the myeloma cell line chosen.

Alternative methods of producing monoclonal antibodies utilize in vitro immunization techniques. Lymphocytes may be harvested frown lymphoid organs, such as spleen or lymph nodes, or from whole blood as peripheral blood lymphocytes. The lymphocytes are put into culture in the presence of the appropriate immunogen. Often immunostimulatory polypeptides will be added to the culture medium concurrently. At various times following the culturing of the lymphocytes in vitro, the lymphocytes are harvested and fused with a myeloma cell line as described above.

Other techniques for producing and maintaining antibody secreting lymphocyte cell lines in culture include viral transfection of the lymphocyte to produce a transformed cell line which will continue to grow in culture. Epstein-Barr virus (EBV) has been used for this technique. EBV transformed cells do not require fusion with a myeloma cell to allow continued growth in culture.

Thymocytes may be used as a feeder layer to condition the medium for the fused cells. Alternatively, peritoneal macrophages or non-immune spleen cells may be used as a feeder layer. Another alternative is to use conditioned medium frown thymocytes or macrophages. Thymocytes may be prepared from juvenile mice less than 8 weeks old. The thymus glands are harvested and minced using techniques which disrupt the thymus gland but are not detrimental to the thymocytes. This procedure is preferably carried out using scissors to mince the tissue, followed by passage of the tissue through a mesh screen. The minced and strained cell material is then harvested by centrifugation. Cell suspensions are made using growth medium. Any remaining connective tissue may be removed by filtration through gauze.

At an appropriate time following the day the cells are fused, tile fused cells (hybridomas) are then analyzed for the production of antibody against the antigen of choice. This "screening" can be done by a wide variety of techniques, including Western blot, ELISA, immunoprecipitation, affect on biological activity assays and immunocytochemical staining. These techniques and others are well described in the literature. (See, for example, J. G. R. Hurrell (ed.), Monoclonal Hybridoma Antibodies: Techniques and Applications, CRC Press Inc., Boca Raton, Fla., 1982.) Introduction of a screening procedure permits further definition of antibodies of useful reactivity. For example, complexes purified from a biological sample of a patient with a bladder cancer may be used in any of the above-named techniques to define antibodies which react, for example, to determinants which are common to patients with file disease.

Hybridomas which secrete antibodies of interest are maintained in culture. The cells are expanded in culture and at the same time may be cloned in such a manner as to obtain colonies originating from single cells. This provides for the monoclonal nature of the antibodies obtained from the hybridomas. A wide variety of techniques exist for cloning cells, including limiting dilution, soft agar cloning and fluorescence-activated cell sorting.

Once clones of cells are obtained, they are re-assayed for the production of the antibody of interest. These cells are then expanded in culture to allow for the production of larger amounts of the antibody. Methods for expansion of the cells include maintaining the cells in culture, placement of the cells in a bioreactor or other type of large-scale cell culture environment, or culturing the cells using various agar or gelatin carrier matrices. Antibodies are then isolated from the cell culture media.

A preferred method of producing large amounts of antibodies involves growing the hybridoma cells in the peritoneal cavity of syngeneic mice, thereby producing ascites fluid. The hybridomas are preferably isolated from the culture media by centrifugation and washed with an iso-osmotic solution, preferably phosphate buffered saline. The cells are then resuspended in an iso-osmotic solution and injected into the peritoneal cavity of an appropriate host animal, preferably a mouse, and allowed to grow within the host animal. The host animal may receive a pre-injection of pristane (2,6,10,14-tetramethylpentadecane) prior to the injection of the hybridoma cells, preferably seven to thirty days prior to the introduction of the hybridomas. Following growth of the cells in the peritoneal cavity, ascites fluid, containing the antibody of interest, is collected.

Antibodies may be purified from conditioned media or ascites fluid by a variety of methods known in the art. These methods include ammonium sulfate precipitation, ion exchange chromatography (see Hurrell, ibid. ) and high pressure liquid chromatography using a hydroxylapatite support (Stanker et al., J. Immunol. Methods 76:157, 1985). A preferred method for purifying antibodies from conditioned media or ascites fluid utilizes a commercially available Protein A-Sepharose CL-4B column or Protein G Sepharose (Pharmacia, Piscataway, N.J.; Sigma, St. Louis, Mo.) or ABX mixed ion exchange resin (JT Baker, Phillipsburg, N.J.). Antibodies may be purified with these columns using conditions suggested by the manufacturer. Typically, the conditioned medium or ascites fluid is dialyzed into Phosphate buffered saline to give a pH of 7.5-8 and applied to the a protein-A sepharose column. The antibodies are eluted by lowering the pH in a stepwise fashion with 100 mM sodium citrate buffers of pit 7, 6, 4.5 and 3.5, respectively. Antibody-containing elements are immediately adjusted to pH 7.4, preferably using a saturated trisodium phosphate solution or concentrated Tris buffer. Alternatively, ABX, a mixed mode ion exchanger is equilibrated with 25 mM MES buffer, pH 5.6, (2-(n-Morpholino) ethane sulfonic acid (Sigma Chem. Co., St. Louis, Mo.). Concentrated conditioned media or ascites is diluted 1:3 in 100 mM MES buffer, pH 15.5, and the pH adjusted to that of the column equilibration buffer. Sample is applied to the column and eluted in equilibration buffer. Bound antibody is eluted with the 25 mM MES buffer, pH 5.6, containing 10% (v/v) of a 25 mM potassium phosphate containing 500 mM ammonium sulfate, pH 5.6, buffer, this is followed by a linear gradient frown 10%-100% (v/v) of the 25 mM potassium phosphate buffer containing 500 mM ammonium sulfate, pH 5.6.

The presence or amount of a complex or one or more polypeptide components of a complex may be determined in a variety of ways, including non-immunological and immunological. Non-immunological methodologies include the use of protein stains such as Coomassie blue or silver stains. In a preferred embodiment, a sample suspected of containing a complex is subjected to SDS-PAGE and identified using a protein stain. Other non-immunological methodologies include the use of radioisotopes and the like as reporter groups. Such methods are amenable to quantification where it is desired to determine the amount.

Alternatively, the presence or amount of a complex or polypeptide component may be detected by immunological means. As used herein, the term "antibody" includes both polyclonal and monoclonal antibodies; and may be an intact molecule, a fragment thereof, or a functional equivalent thereof; and may be genetically engineered. Examples of antibody fragments include F(ab')₂, Fab', Fab and Fv. Detection may be, for example, by Western blot analysis utilizing immobilized complexes or components thereof on nitrocellulose, or Immobilon or similar matrix in conjunction with specific antibodies to the complexes or to individual components of the complexes. Detection can also be achieved by immunoassay. In one embodiment, a complex or polypeptide is isolated from a sample and contacted with an appropriate detection antibody. Complexes may be isolated by capture on a solid support (e.g., heparin agarose or polystyrene or heparin coated on polystyrene) or with a "capture" antibody prior to or simultaneous with a "detection" antibody. In another embodiment, immunocomplexes are formed between an antibody and a complex, without prior purification of the complex. Incubation of a sample with an antibody is under conditions and for a time sufficient to allow immunocomplexes to form. Detection of complexes or polypeptide constituents by immunological means is also amenable to quantification where it is desired to determine the amount of a particular complex or polypeptide constituent.

Detection of one or more immunocomplexes formed between a complex or polypeptide component and an antibody specific for the complex or polypeptide may be accomplished by a variety of known techniques, including radioimmunoassays (RIA) and enzyme linked immunosorbent assays (ELISA).

The immunoassays known in the art include the double monoclonal antibody sandwich immunoassay technique of David et al. (U.S. Pat. No. 4,376,110); monoclonal-polyclonal antibody sandwich assays (Wide et al., in Kirkham and Hunter (eds.), Radioimmunoassay Methods, E. and S. Livingstone, Edinburgh, 1970); the "western blot" method of Gordon et al. (U.S. Pat. No. 4,452,901); immunoprecipitation of labeled ligand (Brown et al., J. Biol. Chem. 255:4980-4983, 1980); enzyme-linked immunosorbant assays as described by, for example, Raines and Ross (J. Biol. Chem. 257:5154-5160, 1982); immunocytochemical techniques, including the use of fluorochromes (Brooks et al., Clin. Exp. Immunol. 39:477, 1980); and neutralization of activity (Bowen-Pope et al., Proc. Natl. Acad. Sci. USA 81:2396-2400, 1984), all of which are hereby incorporated by reference. In addition to the immunoassays described above, a number of other immunoassays are available, including those described in U.S. Pat. Nos.: 3,817,827; 3,850,752; 3,901,654; 3,935,074; 3,984,533; 3,996,345; 4,034,074; and 4,098,876, all of which are herein incorporated by reference.

For detection purposes, the antibodies may either be labeled or unlabeled. When unlabeled, the antibodies find use in agglutination assays. In addition, unlabeled antibodies can be used in combination with other labeled antibodies (second antibodies) that are reactive with the antibody, such as antibodies specific for immunoglobulin. Alternatively, the antibodies can be directly labeled. Where they are labeled, the reporter group can include radioisotopes, fluorophores, enzymes, luminescers, or dye particles. These and other labels are well known in the art and are described, for example, in the following U.S. Pat. Nos.: 3,766,162; 3,791,932; 3,817,837; 3,996,345; and 4,233,402.

Typically in an ELISA assay the target antigen or immobilized capture antibody is adsorbed to the surface of a microliter well. Residual protein-binding sites on the surface are then blocked with an appropriate agent, such as bovine serum albumin (BSA), heat-inactivated normal goat serum (NGS), or BLOTTO (buffered solution of nonfat dry milk which also contains a preservative, salts, and an antifoaming agent). The well is then incubated with a sample suspected of containing specific antibody. The sample can be applied neat, or, more often, it can be diluted, usually in a buffered solution which contains a small amount (0.1%-5.0% by weight) of protein, such as BSA, NGS, or BLOTTO. After incubating for a sufficient length of time to allow specific binding to occur, the well is washed to remove unbound protein and then incubated with an anti-mouse immunoglobulin antibody labeled with a reporter group. The reporter group can be chosen from a variety of enzymes, including horseradish peroxidase, beta-galactosidase, alkaline phosphatase, and glucose oxidase. Sufficient time is allowed for specific binding to occur, the well is again washed to remove unbound conjugate, and the substrate for the enzyme is added. Color is allowed to develop and the optical density of the contents of the well is determined visually or instrumentally.

In one preferred embodiment of the present invention, a reporter group is bound to the antibody. The step of detecting an immunocomplex involves removing substantially any unbound antibody and then detecting the presence or absence of the reporter group.

In another preferred embodiment, a reporter group is bound to a second antibody capable of binding to the antibody specific for a complex of one or more basement membrane components. The step of detecting an immunocomplex involves (a) removing substantially any unbound antibody, (b) adding the second antibody, (c) removing substantially any unbound second antibody and then (d) detecting the presence or absence of the reporter group. Where the antibody specific for the fragment is derived from a mouse, the second antibody is an anti-murine antibody.

In a third preferred embodiment for detecting an immunocomplex, a reporter group is bound to a molecule capable of binding to the immunocomplex. The step of detecting involves (a)adding the molecule, (b) removing substantially any unbound molecule, and then (c) detecting the presence or absence of the reporter group..An example of a molecule capable of binding to the immunocomplex is protein A.

It will be evident to one skilled in the art that a variety of methods for detecting the immunocomplex may be employed within the present invention. Reporter groups suitable for use in any of the methods include radioisotopes, fluorophores, enzymes, luminescers, and dye particles.

The following examples are offered by way of illustration and not by way of limitation.

EXAMPLES Example 1 Latex Agglutination Assays for Basement Membrane Complexes (Bladder Tumor Analyte, BTA) in Urines of Bladder Cancer Patients of Different Stage and Grade

Latex agglutination assays for the detection of the bladder tumor analyte ("BTA") were performed in two different formats, a slide agglutination assay and a colored dipstick agglutination format. Both assays measure, using the stone principle, the presence of BTA in urine which is formed and secreted into urine by transitional cell carcinomas of the bladder.

Latex reagent for use in the slide agglutination assay is prepared as follows. To 750 ml of 49% suspension of 0.25 micron diameter carboxylated polystyrene latex (Morton Thiokol, Morton Thiokol International, Chicago, Ill. is added 2 ml of goat serum from a healthy unimmunized goat which has been diluted 1:10 in 0.85% saline. The mixture is placed in a 56° C. water bath for 60 minutes and stirred using a magnetic stirrer, or similar device, for 18-24 hours at room temperature. Seventy five ml of this stock latex suspension is diluted 1:40 with 2925 ml of 0.013M Glycine Buffer (pH 8.2 containing 0.1% sodium azide) containing 4 g of bovine serum albumin (BSA). This latex suspension is mixed for two hours using a magnetic stirrer or similar device. The suspension is then adjusted to an optical density of 0.31 OD (optical density standard) units at 700 nm, using distilled water as a blank, on a spectrophotometer to yield "Latex reagent". The addition of 12 mg of human gamma globulin (in 20 ml of 0.85% saline) prior to the 56° C. heat treatment step improves agglutinating activity.

Latex agglutination assays were performed by placing 50 μl of urine within a circle or well on a black serology or similar slide. Subsequently 50 μl of working "latex reagent" is placed on the urine sample. The mixture is stirred to the outer edge of the circle using a clean plastic stirrer, and rocked gently for 2 minutes. The slide is examined visually for agglutination of the latex particles. Improved assay performance was obtained by neutralizing urine samples with 10 μl of 1M Hepes buffer, pH 7.8, prior to adding latex reagent.

Latex reagent for use in the dipstick assay is prepared as described below. A stock latex was prepared by adding 12 mg of human IgG to 20 ml of saline solution and then adding this solution to 750 ml of 48% solution of 0.25 micron particles. Two ml of normal goat serum was mixed with 18 ml of normal saline and added to the latex suspension. The stock latex suspension was heated at 56° C. for 1 hour and mixed gently. The latex suspension was allowed to cool to 30° C. and 1.88 g of Brilliant Blue R dye was added and mixed for 18 hours at room temperature.

A working latex was prepared by adding 1 g of sodium azide, 1 gm of glycine, 1.5 g of bovine serum albumin, 30 ml of water soluble yellow dye and 105 ml of stock latex suspension to 3 liters of distilled water. The reagent was adjusted to pH 8.5 and mixed for 2 hours.

Latex agglutination dipstick assays for BTA detection in urine samples were performed by the following procedure. Urine samples (0.5 ml) were neutralized by the addition of 1 drop of 1M Hepes buffer, pH 7.8. Thirty five microliters of this sample was then mixed with 35 μl of the working latex reagent in a plastic well and allowed to react for approximately 30 seconds. Fiber glass dipsticks with controlled pore size glass were now added carefully to the well and the reaction mix allowed to migrate up the dipstick. Urine samples were considered to be positive for BTA if a distinct yellow above blue coloration is observed. A gradually lightening green or green above diffuse blue is considered a negative. BTA dipstick assays on column locations do not use the Hepes neutralization.

Urine samples from patients being monitored for bladder cancer recurrence were tested using either of the above procedures and compared with voided urine cytology ("VUC") performed at the individual clinical sites. VUC is commonly used in the monitoring of bladder cancer patients, but suffers from low sensitivity in the detection of low grade tumors. Several examples where VUC and the latex agglutination assay were compared in a transitional cell carcinoma ("TCC") monitoring situation over a period of time are shown in Table 1 along with the biopsy data and the cystoscopic findings. In this data, initial studies were performed with the slide form of the assay. All subsequent data was performed with the dipstick assay.

                                      TABLE 1                                      __________________________________________________________________________     RELATIONSHIP OF BTA TO VUC, CYSTOCOPY AND                                      BIOPSY IN SELECTED MONITORED PATIENTS                                          CASE                                                                               MONTH                                                                               BTA                                                                               VUC        CYSTOCOPY   BIOPSY                                      __________________________________________________________________________     1   1    -  --         NORMAL      NO                                              6    +  --         PAPILLARY TUMOR                                                                            NEGATIVE                                        11   +  SUSPICIOUS PAPILLARY TUMOR                                                                            Ta GRADE II                                  2* 1    +  ATYPICAL   INVASIVE TUMOR                                                                             T1 GRADE III                                    7    +  --         ERYTHEMA    NEGATIVE                                        9    -  --         NEGATIVE    NEGATIVE                                                *On intravesical                                                               therapy                                                            3   1    +  --         PAPILLARY TUMOR                                                                            Ta GRADE I                                      7    +  REACT CHANGES                                                                             PAPILLARY TUMOR                                                                            NEGATIVE                                        8    +  TUMOR      PAPILLARY TUMOR                                                                            NEGATIVE                                    4   1    -  --         NORMAL      NO                                              7    +  UROTHELIAL CA                                                                             PAPILLARY TUMOR                                                                            Ta GRADE II/CIS                             5   1    -  REACT CHANGES                                                                             ERYTHEMA    NO                                              6    +  UROTHELIAL CA                                                                             NORMAL      NO                                              10   +  UROTHELIAL CA                                                                             TUMOR       TCC                                         6   1    +  REACT CHANGES                                                                             NORMAL      NO                                              3    +  UROTHELIAL CA                                                                             NORMAL      NO                                              7    +  UROTHELIAL CA                                                                             ERYTHEMA    TCC                                             8    +  UROTHELIAL CA                                                                             TUMOR       TCC                                         __________________________________________________________________________

The data indicates that the agglutination assay is capable of detecting complexes in the urine of monitored TCC patients prior to VUC and in some cases precedes diagnosis by cystoscopy. In addition, the reactivity in urine increases as the rumor progresses and decreases upon treatment as would be expected for an analyte representative of tumor burden.

The ability of the BTA slide agglutination assay to detect complexes in urines of different stages and grades of tumor is shown in Tables 2 and 3. The data indicate that the assay detects low grade tumors as well as high grade tumors, but that the detection rate increases with histological grade of the tumor.

                  TABLE 2                                                          ______________________________________                                         SENSITIVITY OF BTA DIPSTICK AND VUC FOR URINES                                 OF TCC PATIENTS OF DIFFERENT                                                   HISTOLOGICAL GRADE                                                             GRADE           BTA     VUC                                                    ______________________________________                                         I               11/19    2/19                                                  II              5/8     2/8                                                    III             12/16   10/16                                                  ______________________________________                                    

Bladder tumors are typically designated as: superficial if papillary (Stage Ta), or surface tumors (Stage CIS), or invasive (Stage T1-T3) if penetrating the basal lamina and eventually the muscle and surrounding tissue. Procedures used in the treatment of bladder cancer are often based on the invasive nature of the tumor and it is therefore important to be able to monitor the types of tumor. The ability of the BTA dipstick test to detect these different types of tumor as compared to VUC in a population of patients being monitored for TCC recurrence is shown in Table 3.

                  TABLE 3                                                          ______________________________________                                         SENSITIVITY OF BTA DIPSTICK AND VUC FOR URINES                                 OF PATIENTS WITH SUPERFICIAL                                                   AND INVASIVE TCC                                                               TUMOR STAGE         BTA     VUC                                                ______________________________________                                         SUPERFICIAL (Ta-CIS)                                                                               16/30   4/30                                               INVASIVE (T1-T3)    13/16   9/16                                               ______________________________________                                    

The data indicates the superiority of the BTA assay in detecting low grade superficial minors as compared to VUC and supports its use as an adjunct test in monitoring tumor recurrence.

Example 2 Gel Filtration of 24 Hour Urines from Patients with Different Stages and Grade of TCC

Twenty four hour voided urines collected from patients with transitional cell carcinoma (TCC) of the bladder and at different stage and grade of disease representative of superficial and invasive tumors, as well as normal urine pools were fractionated as described in the flow diagram shown in FIG. 1.

Twenty four hour urines (usually 500-3500 ml) upon receipt were initially tested using a urine dipstick (Chemstrip, Boehringer Mannheim) for pit, protein, microhematuria and for other urinary analytes, prior to testing in the BTA dipstick agglutination assay. After testing, the urines were treated with protease inhibitors [PMSF (5 mM), iodoacetamide (5 mM), benzamidine (2 mM) and EDTA (25 mM)], preserved with azide (0.1% w/v) and the pH adjusted to pH 7.4 with Tris buffer in order to stabilize against further proteolysis. Urines were then centrifuged and concentrated 50-100X on an Amicon PM30 membrane. The urine concentrate was then applied to an Agarose A1.5M column (2.5×50 cm column in earlier studies and 2.5×100 cm later) and eluted with 20 mM Tris buffered saline (0.13 M) containing EDTA (25 mM) and benzamidine (2 mM). BTA dipstick agglutinating activity, if present, was measured using 35 μl of column fraction instead of urine as described in the assay procedure in Example 1. Activity was eluted at or near the void volume as seen in FIG. 2a for a TCC positive patient. In all cases the agglutinating activity was localized to the void volume. FIG. 2b shows a typical elution profile for a TCC negative patient which indicates little or no protein in the void volume fraction and no BTA activity.

Initial observations pointed to the fact that the positive agglutination reactivity in the void volume of the A1.5M agarose columns of fractionated bladder cancer urines also corresponded to fractions that reacted to several antibodies, although weakly, against native basement membrane proteins such as collagen IV and fibronectin and was indicative of high molecular weight complexes comprised of basal lamina components being present in these tractions.

These complexes were further purified. Active fractions from the A1.5M column were pooled, concentrated on an Amicon PM30 membrane, and applied to an Agarose A15M column (2.5×45 cm) and eluted in the same Tris buffer. Some protein elutes in the void volume but essentially all tile agglutinating activity is in the included volume of the column, as shown in FIG. 3 for a member of TCC positive urines of different stage and grade. A direct correlation exists between the amount of BTA reactive material in urine and the stage/grade of a tumor, i.e., the more advanced the tumor the greater the quantity of BTA reactive material present in urine. This is discussed further in Example 3 below which relates activity in a larger number of gel filtration purified complexes to stage and grade of the tumor and to the molecular events occurring during the generation of the complexes.

Example 3 Relationship of BTA Dipstick Agglutinating Activity and 8D8 Page Profiles of Agarose A15 Fractions to Stage and Grade of Tumor

The BTA active fractions from A15 agarose gel filtration for the different urines were pooled and, if more than one column run was performed, active fractions of all columns for an individual patient were combined so as to represent the total isolated activity for a particular urine. Pools for each of the individual urines were then concentrated on a PM30 membrane and subjected to SDS-PAGE analysis in order to analyze the profile of protein bands present. Briefly, Agarose A15 purified complexes isolated from urines of patients with different stage and grade of TCC were subjected to SDS-PAGE using a 10%12% polyacrylamide resolving gel in combination with a 5.6% stacking gel. Samples were diluted 3:1 in a 4X dissociation buffer (5% 2-mercaptoethanol in buffer mix of 1 ml of 1.5M Tris, pit 6.8, 4.8 ml of 10% SDS, 3.6 ml of Glycerol, 0.1 ml of 1% bromothymol blue and 2.4 ml of distilled water) and heated in a boiling water bath for 5 minutes. Samples were loaded onto gels at 2-10 μg/well along with wells containing molecular weight standards (205 kd-18.5 kd). Samples were run at 200 V constant for˜45 minutes after which gels were removed and fixed in 40% methanol/10% glacial acetic acid prior to staining with either 0.1% Coomassie or BioRad silver stain. After destaining in the acetic acid methanol mix, bands were scanned on a densitometer. Molecular weights were then estimated based on known molecular weight standards included in the gel. Pre-stained molecular weight standards were obtained from BioRad (Richmond, Calif.). Depending on gel porosity, either high molecular weight standards (Myosin--205,000; β-galactosidase--116,500; Bovine serum albumin--80,000; and Ovalbumin--49,500) or low molecular weight standards (Phosphorylase B--106,000; Bovine serum albumin--80,000; Ovalbumin--49,500; Carbonic anhydrase--32,500; Soybean trypsin inhibitor--27,500; and Lysozyme--18,500) were used as per the manufacturers recommendations. Prestained standards ran at higher molecular weights than their unstained. counterparts.

Concentrates were also titered in the BTA dipstick assay by performing doubling dilutions of the pooled fractions in the A15M column buffer and testing in the latex agglutination dipstick assay for positive reactivity. Protein concentrations were determined using a BCA protein assay (BioRad). Specific activities for the different concentrates were then calculated (BTA positive assay titer/BCA protein concentration (mg/ml)) to determine if there was a correlation between the pattern of appearance of SDS bands with both BTA specific activity (which is a measure of the amount of analyte) and stage or grade of tumor development. In addition, comparison of SDS-PAGE gels to those of normal urines, or non-TCC urines enabled the elimination of SDS-PAGE bands that were present in similar fractions from normal urine and therefore did not contribute to the BTA agglutination activity.

In A15 samples from normal urine pools, essentially no SDS-PAGE bands were visible with molecular weights in excess of 100 kd. In the case of TCC patients, however, patterns of high and low molecular weight bands were present that correlate with the progression and extent of disease. A summary of these patterns is given in Table 4 and densitometric scans of gels of A15 fractions of different stage and grade are shown in FIG. 4.

                  TABLE 4                                                          ______________________________________                                         Relationship of BTA Activity in Urine to Invasive Potential of                 Transitional Cell Carcinoma of the Bladder                                     STATUS   TCC      ELECTROPHORETIC BTA                                          FOR TCC  STAGE    OBSERVATIONS    ACTIVITY                                     ______________________________________                                         Negative          No high MW proteins >                                                                          --                                                             100 kd                                                       Low Grade                                                                               Ta       2 High MW proteins                                                                             ±                                         Non-Invasive      appear at 245 kd and 190                                                       kd                                                           Low Grade                                                                               T1       High MW proteins                                                                               +                                            Invasive          disappear and major bands                                                      appear at 165 kd and minor                                                     bands at 140 kd and 125 kd                                                     with lesser changes at                                                         lower MW                                                     High Grade                                                                              T2-T3    165 kd, 140 kd and 125 kd                                                                      ++                                           Invasive          begin to disappear with                                                        appearance of lower MW                                                         bands at 98, 82, 74, 55,                                                       43, 35, 26 and 16 kd                                         ______________________________________                                    

In early stage superficial tumors where invasive potential has not been established or not clearly evident as determined by cystoscopy, there is the appearance of high molecular weight peptides (≧190 kd). In particular, in some non-invasive tumors (Ta) and in cases of chronic epithelial inflammation there is the appearance of two bands at approximately 245 and 190 kd. Some of these tumors are weakly detectable in the BTA dipstick assay. Upon further progression and transition of the disease into an invasive phase, these bands gradually disappear and a major band of molecular weight approximately 165 kd appears along with lesser bands one at 140 kd and another at 125 kd with some minor changes at lower molecular weights. The presence of high BTA dipstick activity corresponds to the appearance of these proteins in particular the 165 kd peptide. As the tumor becomes more aggressive and invasive, these peptides are further degraded with the appearance of lower molecular weight species at approximately 98, 82, 74, 55, 43, 35, and 26 kd with indications of a lower MW band in the range of 16 kd, as evidenced in Western blots and higher percentage polyacrylamide gels. The 165 kd protein does not disappear completely when this transition occurs.

Analysis of the data of BTA specific activity versus the stage or grade of the tumor indicate a high degree of correlation with the stage and, in particular, the grade of the tumor and supports the utility of the BTA agglutination assays and hence the BTA analyte in the prognosis and monitoring of metastatic transitional cell carcinoma of the bladder. FIGS. 5a and 5b show the relationship of stage and grade to activity in gel filtration purified complexes from several 24 hour urines and information on the urines and the mean specific activities versus stage and grade are given in Tables 5 and 6.

                                      TABLE 5                                      __________________________________________________________________________     BTA DIPSTICK SPECIFIC ACTIVITIES OF                                            A15 AGAROSE PURIFIED COMPLEXES                                                                            PROTEIN                                                                              SPECIFIC                                      PATIENT ID                                                                             TCC STATUS  BTA TITER                                                                             μg/ml                                                                             ACTIVITY                                      __________________________________________________________________________     NEG POOL 1                                                                             --          <1     3600  0                                             NEG POOL 2                                                                             --          <1     50    0                                             NEG POOL 3                                                                             --          <1     <10   0                                             WC      --          <1     600   0                                             JCH     --          <1     175   0                                             RES     BPH         <1     629   0                                             LJB     CYSTITIS    2      350   5.7                                           JP      Ta GRADE I  8      3600  2.22                                          WEM(1)  Ta GRADE I  4      890   4.49                                          HO      Ta GRADE I  <1     810   0                                             ER      Ta GRADE I  1      220   4.55                                          CDU     Ta GRADE I  4      300   13.34                                         TCH     Ta GRADE I  128    42800 2.99                                          HB      Ta GRADE II 4      302   13.25                                         CJS     Ta GRADE II 8      195   41.03                                         ELS     CIS         16     544   29.41                                         CES     CIS         2      740   2.7                                           WEW     CIS         64     3060  20.92                                         GWH     CIS         256    5565  46                                            OCS     T2 GRADE III                                                                               64     2640  24.24                                         MVA     T1 GRADE III                                                                               32     1815  17.63                                         OB      T1 GRADE II 32     1050  30.48                                         RN      T2 GRADE III                                                                               8      155   51.61                                         WAF     T2 GRADE III                                                                               128    5700  22.46                                         DM      T3 GRADE III                                                                               512    15600 32.82                                         AS      T3 GRADE III                                                                               64     1750  36.57                                         RB      T3 GRADE III                                                                               16     573   27.92                                         DEW     T3 (GRADE unknown)                                                                         64     3800  16.84                                         HS      T3 GRADE III                                                                               8      1695  4.72                                          POM     Ta GRADE III                                                                               64     2410  26.56                                         __________________________________________________________________________

                  TABLE 6                                                          ______________________________________                                         RELATIONSHIP OF BTA DIPSTICK SPECIFIC ACTIVITY                                 TO STAGE AND GRADE OF TCC                                                      MEAN SPECIFIC ACTIVITY (Titer/mg) VS                                           STAGE AND GRADE                                                                ______________________________________                                         NORMALS          (n = 7)  0.8                                                  GRADE I          (n = 6)  4.6                                                  GRADE II         (n = 3)  28.3                                                 GRADE III        (n = 9)  27.2                                                 Ta               (n = 9)  12.1                                                 CIS              (n = 4)  24.8                                                 T1               (n = 2)  24.1                                                 T2               (n = 3)  32.8                                                 T3               (n = 5)  23.8                                                 ______________________________________                                    

Example 4 Heparin Agarose Fractionation and SDS Profiles of Complexes

To further pinpoint the peptides contributing to the BTA activity, positive samples after agarose A15M were further fractionated on Heparin agarose which is known to bind fibronectin and laminin and has been shown to bind the BTA reactive complexes with high affinity. The active fractions were again analyzed by SDS gel electrophoresis. From these studies, protein bands were clearly identified as contributing to the core agglutinating activity.

Initially, 1×20 cm Heparin agarose columns were equilibrated with 20 mM phosphate buffer, pH 7.4. Agarose A15 fractions were dialyzed overnight against this buffer and then applied to the heparin agarose column. 2-5 ml of sample was applied to the column and the column was washed with equilibration buffer to elute non binding material that was devoid of BTA activity. The column was now eluted with a 0-500 mM stepwise gradient of NaCl in equilibration buffer (0,50,150 and 500 mM). The BTA activity eluted in 0-150 mM salt. A second peak of activity was also seen when a 500 mM wash was used. A typical elution profile from Heparin agarose when using a phosphate buffer system is shown in FIG. 6. This shows the fractionation of a high stage and grade (T3 Grade III) tumor.

Cytokeratin (a previously described potential marker for bladder cancer) was detectable in the flow through of the column using a cytokeratin antibody clone 8.13 and was not detectable in the BTA reactive fractions. Both of the agglutinating fractions were then concentrated on an Amicon PM10 membrane and re-dialyzed against 20 mM sodium phosphate buffer, pH 7.4, and applied separately to a 1×20 cm DEAE-Biogel A column (BioRad, Richmond, Calif.). Fractions were again eluted with 20 mM phosphate buffer, pH 7.4, containing 0, 50, 150 and 500 mM sodium chloride. Fractions were tested for BTA activity and in an ELISA assay with anti-type IV collagen and anti-fibronectin antibodies. The majority of the agglutinating activity in the 150 mM fraction from heparin agarose also appeared in the 150 mM fraction from DEAE-Biogel A with a small portion of the activity in the 500 mM fraction. The opposite was seen (FIG. 7) with the 500 mM Heparin agarose fraction after separation on DEAE-Biogel A. Both the 150 and 500 mM DEAE fractions showed reactivity in the slide agglutinating assay and were reactive with antibodies to Type IV collagen and fibronectin although weakly thus indicating the two proteins purifying as a complex.

In later studies, 5-10 ml heparin agarose columns were equilibrated with 25 mM Tris, pH 7.4. Agarose A15 fractions were dialyzed overnight against the equilibration buffer and applied to the heparin agarose column. 2-5 mls of sample was applied to the column and the column was washed with equilibration buffer to elute non-specific material that was devoid of BTA activity. The column was now eluted with a 0-500 mM linear gradient of NaCl in equilibration buffer. The BTA activity eluted in 100-150 mM salt. A second peak of activity was also seen when a 500 mM NaCl/25 mM phosphate buffer, pH 7.4, elution buffer was used. Typical elution profiles from heparin agarose when using a Tris buffer system are shown in FIG. 8. These represent fractionations of two urines representative of high and low grade TCC and one negative urine. Application of a salt gradient results in activity appearing as a trailing shoulder to a major protein peak at a salt concentration of 100-150 nM. This shoulder of activity in the 100-150 mM fraction was absent in BTA negative urines and in the case of a Ta urine patient, HB, which had little or no BTA activity. Earlier studies showed that the peak eluting in the flow-through which was devoid of BTA activity, was enriched for cytokeratins another marker which has been utilized as a bladder cancer marker. The complexes derived from bladder cancer patients, however, react poorly with antibodies to collagen IV and fibronectin as outlined in earlier studies on heparin agarose (see above).

An example of the SDS polyacrylamide analysis of heparin agarose fractions with BTA activity from Tris buffer eluted heparin agarose columns is shown in FIG. 9. The SDS bands seen were absent from a normal urine pool and appear to represent the core components of the complexes. The molecular weights again show the same group of polypeptides described in Example 3.

Example 5 Development and Characterization of Antibody (1B4) to Complex

BALB/c mice were immunized with 100 gl of a 1:1 mixture of A15 agarose purified material from a TCC patient with T2 grade III tumor with Freund's complete adjuvant. Two secondary immunizations at monthly intervals with the 165 kd material isolated by SDS/PAGE electroelution from the same patient were performed in 1:1 mixture in Freund's incomplete adjuvant. A final boost of electroeluted material in Freund's incomplete adjuvant was administered after a further 3 weeks and one week prior to sacrificing the mice.

Spleen cells were prepared in serum-free RPMI 1640 medium and mixed with P3/NS-1/1-Ag4-1 cell line in a Spleen cell/NS-1 cell ratio of 5:1 in a total volume of 25 ml. This cell mixture was centrifuged at 1200 g for 10 minutes at room temperature. Supernatant was removed and the cells resuspended in serum free medium and re-centrifuged. Cells were washed three times in this manner. After removing the final supernatant, the cell pellet was gently resuspended in the residual medium by gently tapping the tube and warming in 37° C. water bath for 1 minute. The fusion procedure was initiated by the addition of 300 μl of 45% (w/v) polyethylene glycol (Boehringer Mannheim) at 37° C. over a period of 45 seconds while agitating gently. Cells were gradually diluted by the addition of 15 ml of serum-free medium over a period of 90 seconds. Cells were centrifuged gently and the supernatant removed. Cells were then gently re-suspended in 70 ml of HAT medium (no vortexing) and dispensed into 96 well plates at 100 μl/well. Plates were then incubated at 37° C. for 7-10 days after which supernatants from hybridoma containing wells were tested by ELISA against a panel of electroeluted antigens of differing molecular weights from the original A15 agarose isolated immunogen and commercially available basement membrane proteins. Wells were selected on the basis of their reactivity with A15 antigens and non- reactivity with intact basement membrane proteins.

Selected wells were grown up in ILPM11640 medium containing 20% Fetal bovine serum, single cloned and screened for activity against the basement membrane proteins and high molecular weight complexes from a panel of A15 antigens from several TCC positive and negative patients. Cell lines were single cloned a total of 3 times and in each case screened as above.

For screening purposes, 96 well plates were coated with the basement membrane proteins human fibronectin, laminin and collagen IV in addition to fibrinogen and A15 purified complexes from TCC positive and negative urines as well as electroeluted material from TCC positive urines. Coating in each case was performed at 4 μg/ml in carbonate/bicarbonate buffer, pH 9.6, using 100 μl/well of antigen and, after overnight incubation of the plates, were blocked in PBS containing 1% bovine serum albumin. Clones were selected for lack of reactivity to basement membrane proteins, fibrinogen and A15 purified urines of TCC negative patients, but for positive reactivity with A15 material from TCC positive urines. While screening supernatants, 50 μl of hybridoma supernatant was added to wells containing the appropriate antigen and incubating for 1 hour at room temperature. Wells were then aspirated and washed three times in PBS-Tween buffer after which goat anti-mouse IgG horse radish peroxidase conjugate was added to the wells and the plates incubated for a further 1 hour at room temperature. Plates were then washed 3 times in PBS-Tween and the presence of bound horse radish peroxidase conjugate detected using TMB substrate. Reactions were stopped with the addition of 100 μl of 1N H₂ SO₄. Plates were finally read at 450 nm in an ELISA reader. Control wells with antibodies to basement membrane proteins were used when appropriate. Antibody 1B4 and similar clones 3D6, 1A3 and 8H2 all were reactive with the electroeluted 165 kd component of the complex, but were non-reactive with human Collagen IV, Laminin, fibronectin and fibrinogen as shown in Table 7.

                  TABLE 7                                                          ______________________________________                                         ELISA REACTIVITIES OF BTA CLONES WITH                                          BASAL LAMINA AND RELATED PROTEINS                                                            ELISA REACTIVITY (OD 450)                                        SOLID PHASE ANTIGEN                                                                            1B4     3D6      8H2   1A3                                     ______________________________________                                         Collagen IV     0.01    0.017    0.005 0.004                                   Fibronectin     0.01    0.005    0.008 0.013                                   Laminin         0.056   0.027    0.026 0.061                                   Fibrinogen      0.160   0.101    0.07  0.155                                   Electroeluted 165 kd                                                                           >3.0    >3.0     >3.0  >3.0                                    ______________________________________                                    

Reactivity of the antibodies with purified complexes from urines and with the urines themselves is described in Example 8.

The 1B4 antibody was also shown to inhibit both dipstick and slide agglutination activity directly in urine samples.

1B4 antibody was also tested for reactivity against fractions from a heparin agarose fractionation of the urine of a patient with TCC to determine if reactivity is located in the BTA reactive fractions. The data (FIG. 10) shows that 1B4 reactivity is located in the same salt fractions as seen in Example 4 further demonstrating the reactivity of the 1B4 antibody with the complexes.

The 1B4 antibody was isotyped using Mabcheck (Sterogene, Calif., USA) and shown to be of the IgGI(K) type. The cell line which produces antibody 1B4 was deposited with American Type Culture Collection (Rockville, Md., USA) and designated as ATCC No. 11389.

The procedures described above for developing antibodies to the complexes is also applicable to the development of antibodies to the individual components. These proteins can be isolated by electroelution from the complexes and used as immunogens, followed by screening for lack of reactivity to basal lamina proteins but with activity to urines, or isolated fractions of urines, from bladder cancer patients.

Example 6 Elisa Reactivity of 1B4 with A15 Purified Fractions of Patients with Different Stage and Grade of Cancer

A. Heparin Capture ELISA

Based on the fact that the complexes have a high affinity for heparin, assays were performed that utilized heparin as a solid phase to capture the complexes from urine samples or frown gel filtration purified complexes.

Ninety-six well ELISA plates were coated overnight with 100 μl of Heparin (4 μg/ml) in 50 mM carbonate/bicarbonate buffer, pH 9.6, and aspirated dry. Gel filtration purified (Agarose A15 ) samples from urines of patients with different stage and grade of TCC were diluted to 4 μg/ml in 25 mM Tris-HCl, pH 7.8. One hundred microliters of this dilution was added to the heparin coated plates and incubated at 37° C. for two hours. Plates were then aspirated and 100 μl 1B4 antibody (1-2 μg/ml) was added to each of the wells and plates incubated for 2 hours at room temperature. Plates were then washed 3 times in phosphate buffered saline containing 0.1% Tween 20 prior to the addition of 100 μl of a 1/2000 dilution of goat anti-mouse IgG-horse radish peroxidase (HRP) conjugate in phosphate buffered saline containing 0.1% Tween 20 and 0.1% bovine serum albumin. Plates were then incubated for 1 hour at room temperature then washed 3 times in PBS-Tween. Detection of HRP-labeled immunocomplexes in the wells was achieved by adding 100 gl of TMB substrate to the well, incubating for 30 minutes at room temperature, then stopping the reaction by adding 100 μl of 1N H₂ SO₄. Wells were read at 450 nm in an ELISA reader.

FIG. 11 shows the reactivity of 24 different A15 purified complexes (16 TCC positives and 8 TCC negatives). Of the 16 positives, all were detected by the heparin capture EIA. Of the negatives, only one showed some reactivity which was shown to be a Stage D prostate cancer which had metastasized beyond the prostate. FIG. 11 also shows that the overall ELISA reactivity appears to increase as the grade increases as might be expected from the data in previous examples. The samples from the CIS patients, which typically have high grade tumors, were also highly reactive.

B. Non-Heparin ELISA

A15 purified fractions were diluted to 4 μg/ml with 50 mM carbonate/bicarbonate coating buffer, pit 9.6, and coated onto the wells of a 96 well microtiter plate and incubated overnight at 4° C. Plates were then aspirated and 100 μl of blocking buffer (Phosphate buffered saline, pH 7.4, containing 2% BSA) was added and the plates incubated for 90 minutes. The wells were then aspirated and 100 μl of 1B4 antibody (1-2 μg/ml) in phosphate buffered saline pH 7.4 containing 0.1% (v/v) Tween 20 and 0.1% (w/v) bovine serum albumin was added to each of the wells and the plates incubated for a further 2 hours at room temperature. After washing the plates 3 times in phosphate buffered saline containing 0.1% Tween 100 μl of goat anti-mouse IgG-horse radish peroxidase conjugate (1/2000 dilution) in phosphate buffered saline, pH 7.4, containing 0.1% bovine serum albumin and 0.1% Tween 20 was added to each of the wells and the plate incubated at room temperature for 1 hour. Plates were again washed three times as before prior to adding TMB substrate to each of the wells. Color was allowed to develop for 30 minutes at which time the reaction was stopped by the addition of 100 μl of 1N H₂ SO₄ and read on an ELISA reader at 450 nm.

FIG. 12 shows the reactivity of several TCC positive and negative urines with the 1B4 antibody where A15 material is isolated from these urines and is coated directly onto the wells of a polystyrene plate as described in the above procedure. Again, differentiation of TCC positive and negative urines was possible, although the signal was diminished as compared to the heparin capture ELISA when urines are used directly.

Example 7 ELISA Reactivity of 1B4 Related Subclones with Basement Membrane Complexes.

From the same fusion as the 1B4 clone was derived, several other clones or sister clones were developed and tested in ELISA assays as described above, against A15 purified material and also against urines directly. Of particular note are the sister clones 1A3 and 3D6 isolated from the same well as 1B4. Another clone 8H2 was derived from the same fusion as 1B4. Clone 12F3 was isolated from another mouse immunized and fused in the similar way to that from which the 1B4 clone was derived. The clones 12F3 and 8H2 while having similar ELISA reactivity to 1B4 do have differences in their reactivity in Western Blot analyses that indicate that they bind to different epitopes and therefore useful in sandwich ELISA assays. FIG. 13 shows the ELISA activities of these clones as compared to 1B4. Information on the differences in Western blot analysis is given in Example 10 below.

Example 8 ELISA Reactivity of 1B4 with Urines from Bladder Cancer Patients

Heparin Capture ELISA

Ninety-six well ELISA plates were coated overnight with 100 μl of heparin (4 μg/ml) in 50 mM carbonate/bicarbonate buffer, pH 9.6, and were aspirated dry. Urines were buffered by adding 1 part of 500 mM Tris-HCl buffer, pH 7.4, to 4 parts of urine for a final concentration of 100 mM Tris buffer. One hundred microliters of this dilution was added to a heparin coated plate. Plates were incubated at 37° C. for 2 hours. Plates were then aspirated and 100 μl 1B4 antibody (1-2 μg/ml) in phosphate buffered saline containing 0.1% Tween 20 and 0.1% bovine serum albumin was added to each of the wells and plates incubated for 2 hours at room temperature. Plates were then washed 3 times in phosphate buffered saline containing 0.1% Tween 20 prior to the addition of 100 μl of a 1/2000 dilution of goat anti-mouse IgG-horse radish peroxidase (HRP) conjugate in phosphate buffered saline containing 0.1% Tween 20 and 0.1% bovine serum albumin. Plates were then incubated for 1 hour at room temperature then washed 3 times in PBS Tween. Detection of HRP-labeled immunocomplexes in the wells was achieved by adding 100 μl of TMB substrate to the well incubating for 30 minutes at room temperature then stopping the reaction by adding 100 μl of 1N H₂ SO₄. Wells were read at 450 nm in an ELISA reader.

FIG. 14 shows the ELISA reactivity of positive and negative urines when tested in this assay format and supports the use of the 1B4 antibody in the detection of TCC positive urines.

Example 9 1A3 Dipstick Reactivity with Urines from Bladder Cancer Patients

Clone 1A3 is a sister clone to 1B4 with identical properties. This antibody was purified on Protein A sepharose and bound passively to latex particles as described below.

150 ml of de-ionized water was added to 50 ml of 48% Lytron 5450 latex suspension (Morton Thiokol International) and centrifuged for 2 hours at 8000 rpm. This wash step was repeated a second time. The latex was then re-suspended to a 10% (w/v) in 10 mM phosphate buffered saline, pH 7.4. Sixty five microliters of purified 1A3 monoclonal antibody (300 μg/ml) in 10 mM phosphate buffered saline was then added first to 10 ml of 10% Lytron 5450 particles followed by 100 mg of bovine serum albumin as a blocking agent. The latex suspension was mixed for 6 hours at room temperature on a rotator. Brilliant blue R (Sigma Chemical Co., 5 mg) was now added to the mixture and the suspension mixed for a further 1 hour. This constituted the stock latex reagent.

Following incubation and blocking with BSA, 1 ml of the stock latex was mixed with 9 ml of 0.1M glycine buffer, pH 8.2, containing 0.075% Bovine serum albumin and 1 ml/liter of yellow food coloring (Crescent). This constituted the working latex reagent.

To test the reactivity of the antibody coated latex, 20 μl of patient urine was mixed with 80 μl of working latex and mixed in a well comparable to that used for the BTA assay in Example 1. After letting the reagent sit for 20 seconds at room temperature a controlled pore size glass fiber dipstick was added to the reaction mix. The dipsticks were interpreted as positive or negative in the same manner as the dipstick assays described in Example 1. Urine samples were also tested in the buffered urine BTA dipstick assay as described in Example 1. Samples were chosen that were borderline positive or false negative in the BTA dipstick assay.

                  TABLE 8                                                          ______________________________________                                         COMPARISON OF 1A3 AND BTA LATEXES                                              IN DIPSTICK ASSAYS                                                                           DIPSTICK REACTIVITY                                              SAMPLE ID                                                                               IA3 Latex  BTA Latex  TCC STATUS                                      ______________________________________                                         DS       +          +          TCC+                                            SS       +          -          TCC+                                            TB       +          +          TCC+                                            GD       +          ±       TCC+                                            CDU      +          -          TCC+                                            LWN      +          ±       TCC±                                         ABB      -          -          TCC-                                            RG       -          -          TCC-                                            AN       -          -          TCC-                                            JK       -          -          TCC-                                            RT       -          -          TCC-                                            DFS      -          -          TCC-                                            AM       -          -          TCC-                                            SG       -          Stage C1                                                                                  Prostate CA                                     UTX025   -          -          BPH/TCC-                                        IC       +          +          Stage D3                                                                       prostate CA                                     NR       +          +          Ureter Stone/TCC-                               ______________________________________                                    

1A3 antibody coated latex provided improved sensitivity over the normal BTA latex with comparable specificity on the small group of samples tested and provides an example of immunological detection of the complexes.

Example 10 Western Blot Reactivity of 1B4 and Other Clones with Complexes Isolated from Urines of Bladder Cancer Patients

Samples were run in SDS-PAGE gels according to Example 3 using˜10 μg/well of protein. Immobilon-P membranes were equilibrated in SDS-PAGE running buffer (25 mM TRIS, 192 mM glycine with 0.1% SDS) prior to the removal of the SDS-PAGE gel. Gels were then blotted onto the immobilon-P membrane using a BioRad Mini-Trans blot system. Electrophoretic transfer was performed at 250 mA constant for 2 hours. The membranes were then removed and placed in phosphate buffered saline containing 2% BSA as blocking agent for at least 2 hours at room temperature. The blot was then rinsed with phosphate buffered saline containing 0.1% Tween 20 (PBS-Tween). Antibody 1B4 or other clones (˜2 μg/ml) was added in PBS-Tween and the membranes incubated for 2 hours at room temperature while gently rocking on a rotating rocker. The blot was then washed with PBS-Tween for 10 minutes. Alkaline phosphatase labeled goat anti-mouse antibody was now added in PBS-Tween for 60 minutes at room temperature. The blot was now washed three times for 10-15 minutes with PBS-Tween then washed two times in 50 mM TRIS, 5 mM MgCl₂, pH 9.0. Blots were developed using a BCIP/NBT substrate/Chromogen solution containing 100 μg BCIP/ml, 200 μg NBT/ml in 50 mM TRIS, 5 mM MgCl₂, pH 9.0. Band coloration was allowed to proceed until a pinkish background appears at which time the blots were washed in PBS-Tween and allowed to dry in the dark. Blots were scanned on a densitometer.

A Western blot for the 1B4 antibody on a 12% SDS-PAGE gel and related clones on an 11% SDS-PAGE gel versus TCC positive fractions is shown in FIG. 15, Panels A and B, respectively. A series of monoclonal antibodies to the BTA complexes isolated as described in Example 5 were used in Western Blot analyses as described above, using heparin agarose fractions from a patient with active TCC as the target antigen. Depending on antigen load, there are typically six bands that appear to be hit by the BTA monoclonal antibodies, depending on which clone is used. Monoclonal antibodies 1B4 and 3D6 hit bands at 82, 26, and 18 kd, with smaller bands at 98kd, 32kd and 165kd upon higher antigen loads. Monoclonal antibodies 8H2 and 12F3 hit the same six main bands as 1B4, however, they hit the 98kd and 32kd stronger than 1B4. Occasionally there is evidence of a nonspecific band in the 16kd region. All the BTA monoclonal antibodies tend to hit the higher molecular weight (165kd) component of the complex upon higher antigen load. The data indicates that all four antibodies described hit the same complex but at different sites, and are reactive with epitopes that are present on interrelated components of a proteolytic degradation complex.

From the foregoing, it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. 

We claim:
 1. A method for determining the invasiveness of a bladder tumor, comprising the steps of:(a) isolating a urine sample from a warm-blooded animal suspected of possessing a bladder tumor; (b) detecting in said sample the polypeptide composition of a complex which includes basement membrane components, said complex being reactive with antibody 1B4 (ATCC No. 11389) and comprising polypeptides selected from a group of polypeptides with approximate molecular weights of 245,000; 190,000; 165,000; 140,000; 125,000; 98,000; 82,000; 74,000; 5,000; 43,000; 35,000; 26,000; and 16,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and (c) determining the invasiveness of the bladder tumor based on the polypeptide composition of said complex.
 2. A method for determining the invasiveness of a bladder tumor, comprising the steps of:(a) isolating a urine sample from a warm-blooded animal suspected of possessing a bladder tumor; (b) measuring in said sample the amount of a first polypeptide of a complex which includes basement membrane components said complex being reactive with antibody 1B4 (ATCC No. 11389) and, said first polypeptide having an approximate molecular weight of 165,000; 140,000; or 125,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; (c) measuring in said sample the amount of a second polypeptide of said complex, said second polypeptide having an approximate molecular weight of 98,000; 82,000; 74,000; 55,000; 43,000; 35,000; 26,000; or 16,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and (d) calculating the ratio of the amount of said first polypeptide to the amount of said second polypeptide, and determining therefrom the invasiveness of the bladder tumor.
 3. The method of claim 2 wherein said first polypeptide is said polypeptide having an approximate molecular weight of 165,000.
 4. The method of claim 2 wherein said second polypeptide is said polypeptide having an approximate molecular weight of 43,000.
 5. The method of claim 2 wherein said second polypeptide is said polypeptide having an approximate molecular weight of 98,000.
 6. The method of claim 2 wherein said first polypeptide is said polypeptide having an approximate molecular weight of 165,000 and wherein said second polypeptide is said polypeptide having an approximate molecular weight of 43,000.
 7. The method of claim 2 wherein said first polypeptide is said polypeptide having an approximate molecular weight of 165,000 and wherein said second polypeptide is said polypeptide having an approximate molecular weight of 98,000.
 8. A method for determining the invasiveness of a bladder tumor, comprising the steps of:(a) isolating a urine sample from a, warm-blooded animal suspected of possessing a bladder tumor; (b) measuring in said sample a polypeptide of a complex which includes basement membrane components, said complex being reactive with antibody 1B4 (ATCC No. 11389) and comprising polypeptides selected from a group of polypeptides with approximate molecular weights of 165,000; 140,000; 125,000; 98,000; 82,000; 74,000; 55,000; 43,000; 35,000; 26,000; and 16,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; and (c) determining therefrom the invasiveness of the bladder tumor.
 9. A method for determining the invasiveness of a bladder tumor, comprising the steps of:(a) isolating a urine sample from a warm-blooded animal suspected of possessing a bladder tumor; (b) measuring in said sample the amount of a complex which includes basement membrane components, said complex being reactive with antibody 1B4 (ATCC No. 11389) and comprising polypeptides selected from a group of polypeptides with approximate molecular weights of 245,000; 190,000; 165,000; 140,000; 125,000; 98,000; 82,000; 74,000; 55,000; 43,000; 35,000; 26,000; and 16,000 as determined by sodium dodecyl sulfatepolyacrylamide gel electrophoresis; and (c) determining therefrom the invasiveness of the bladder tumor. 